Fuel Delivery Quantity, Checking,

Fuel Delivery Quantity, Checking,

Special tools, testers and auxiliary items required

• Pressure Tester (Diesel) (VAS 6551)

• Container, 3L with a Measuring Scale

• Vehicle Diagnostic Tester

Test Conditions:

• The fuses must be OK.

• Battery voltage is at least 12 volts

• All electrical consumers such as, for example, lights and rear window defogger, must be turned off.

- Disconnect the connector - A - from the auxiliary fuel pump/fuel pump 2.






- Disconnect the fuel supply line quick-release coupling which is black or with a black mark - A -. Disconnecting the coupling. Refer to => [ Coupling, Disconnecting ] Coupling, Disconnecting.






- Connect the hose (VAS 6550/1) from the pressure tester to the fuel supply line - A -.

- Guide the other open end of the hose into the measuring container.

- Connect the vehicle diagnostic tester and perform the guided function "Check Electric Fuel Pumps".

• The fuel pump now runs for 30 seconds.

- When it is finished, check the delivered quantity of fuel in the container.

Specified value: at least 1000 ml/30 seconds.

If the specified value is not obtained:

- Check the fuel supply line between the fuel pump and engine compartment for kinks, pinching or damage.

- Replace the faulty line if necessary and repeat the test.

- Continue as described if there are no kinks, pinching or damage.

- Remove the rear seat bench.

- Fold the carpet to the side or towards the front.

- Remove the cover from the fuel delivery unit.

- Disconnect the fuel supply line, which is black or has a black mark - A - from the fuel delivery unit.






- Connect the hose (VAS 6550/1) from the pressure tester to the fuel supply line - A -.

- Guide the other open end of the hose into the measuring container.

- Connect the vehicle diagnostic tester and perform the guided function "Check Electric Fuel Pumps".

• The fuel pump now runs for 30 seconds.

- When it is finished, check the delivered quantity of fuel in the container.

Specified value: at least 1000 ml/30 seconds.

If the specified value is again not obtained:

- Check the fuel pump voltage supply, refer to => [ Voltage Supply, Checking ] Voltage Supply, Checking and the current draw, refer to => [ Current Draw, Checking ] Current Draw, Checking of the fuel pump.